<!DOCTYPE html>
<html>
<head>
	<title>hello world</title>
</head>
<body>

	<h1>Hello World!</h1>

	<style type="text/css">
		body {
  			background-color: #a3d5d3;
		}

	</style>

	<script type="text/javascript">
		document.getElementsByTagName("h1")[0].style.fontSize = "80px";
	</script>

</body>
</html>